For Heidegger in Being and Time there are two modes of being-in-the-world: present-at-hand (extant) and ready-to-hand (handy) . Present-at-hand is the normal objective world of science. Ready-to-hand is another completely different mode of relating to beings in the world that is not objective, but rather based on use. This approach is called by Heidegger circumspective concern with a view to taking in the totality of the technological infrastructure. One difference between these two modes is the set-like approach verses a mass-like approach. Heidegger says twice that you cannot have a equipment, Equipment is a mass (non-count) term. Heidegger is saying that when we are concerned with use of the technological infrastructure then there is a different modality for relating to things than is the normal objective way of relating to things in Science. The difference is between two kinds of knowledge identified by Aristotle which were Episteme of Science verses Techne of Poiesis. Another mode that Aristotle identifies is Phronesis of Praxis which is identified at the nature of Dasein itself which is different from either the Pure Being of Objectivity of Science (Parmenides) and the Process Being of use of the technological infrastructure which is dynamic (Heraclitus) and practical with regard to building, making, and producing associated with the Readiness-to-hand of equipment.